Several Agave species have played an important ethnobotanical role since prehistory in Mesoamerica and semiarid areas to the north, including central Arizona. We examined genetic variation in relict Agave parryi populations northeast of the Mogollon Rim in Arizona, remnants from anthropogenic manipulation over 600 years ago. We used both allozymes and microsatellites to compare genetic variabil...

For more than a decade, scientists have argued about the warmth of the current interglaciation. Was the warmth of the preindustrial late Holocene natural in origin, the result of orbital changes that had not yet driven the system into a new glacial state? Or was it in considerable degree the result of humans intervening in the climate system through greenhouse gas emissions from early agricultu...

[1] Regional air-sea fluxes of anthropogenic CO2 are estimated using a Green’s function inversion method that combines data-based estimates of anthropogenic CO2 in the ocean with information about ocean transport and mixing from a suite of Ocean General Circulation Models (OGCMs). In order to quantify the uncertainty associated with the estimated fluxes owing to modeled transport and errors in ...

Humans have a profound effect on fire regimes by increasing the frequency of ignitions. Although ignition is an integral component of understanding and predicting fire, to date fire models have not been able to isolate the ignition location, leading to inconsistent use of anthropogenic ignition proxies. Here, we identified fire ignitions from the Moderate Resolution Imaging Spectrometer (MODIS)...

[1] The anthropogenic CO2 accumulation rate for the North Atlantic Ocean was estimated on the basis of the decrease in the dC of the dissolved inorganic carbon measured between cruises in 1981 (Transient Tracers in the North Atlantic), 1993 (OACES) and 2003 (Repeat Hydrography). A mean depth-integrated dC change of 15.0 ± 3.8% m yr 1 was estimated by applying a multiple linear regression approa...

A Lagrangian approach based on a physical-biogeochemical modeling was used to compare the potential transfer of cadmium (Cd) from natural and anthropogenic sources to plankton communities (Cd-uptake) in the North-West African upwelling. In this region, coastal upwelling was estimated to be the main natural source of Cd while the most significant anthropogenic source for marine ecosystem is prov...

Distributions of anthropogenic signatures (impacts and activities) are mathematically analysed. The aim is to understand the Anthropocene and to see whether anthropogenic signatures could be used to determine its beginning. A total of 23 signatures were analysed and results are presented in 31 diagrams. Some of these signatures contain undistinguishable natural components but most of them are o...

Mercury is released in the environment by various natural and anthropogenic activities. As mercury toxic, presence of high levels a major concern. One source humans dental amalgam fillings. Dental has been used for ages clinics hospitals restoring defective decayed teeth. This raises concern regarding use its disposal. The purpose this article to sensitize people about hazards mercury, make the...